The pmd_devmap() check in check_pmd_state() is redundant because the only user of pmd_devmap were device dax and fs dax. However all callers of check_pmd_state() first call thp_vma_allowable_order() to check if the vma should be scanned. Except when called from a page fault this always returns 0 for dax vma's, hence we would never expect to see a pmd_devmap entry. Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> --- Changes from v2: - Update commit message to better reflect why the check was redundant --- mm/khugepaged.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 15203ea..d45d08b 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -945,8 +945,6 @@ static inline int check_pmd_state(pmd_t *pmd) return SCAN_PMD_NULL; if (pmd_trans_huge(pmde)) return SCAN_PMD_MAPPED; - if (pmd_devmap(pmde)) - return SCAN_PMD_NULL; if (pmd_bad(pmde)) return SCAN_PMD_NULL; return SCAN_SUCCEED; -- git-series 0.9.1
